The real Spartacus struck glorious blows against Rome, but his slave rebellion ended in death and defeat. After the eight splendid Lords defeats on Whitehall's social insecurity plans, will the #spartacusreport activists on Twitter who inspired them have achieved something more enduring?

With the welfare reform bill still pinging and ponging between the houses of parliament – there's another vote expected on Wednesday – the final verdict is not quite in, but the government has already clawed back most of the ground. Specific amendments – which would, for example, have safeguarded the benefit rates of disabled children and their entitlements when they reach adulthood – have given way to vague ministerial commitments to undertake some form of review. The great battle to double the proposed time limit on the main incapacity benefit from one to two years has ended in an amendment that gives Whitehall the power to postpone the cut-off at some later date – in the event that it has a rethink. No wonder ministers were happy to accept that one.

Plans to charge lone parents for chasing their child maintenance ran into cross-party lordly resistance. Here, the maximum fees charged in the first instance will be reduced from £100 to £20, but – again – the principle stands.

That leaves the so-called bedroom tax as the one area still in contention. This would force social tenants, especially parents whose children have flown the nest, to move out of homes with a spare room. Even if the Lords secure some concession here, they are now haggling over greatly diluted protection.

The immediate reason the new Spartacus rebellion has all but folded has to do with obscure parliamentary rules – specifically, conventions on the Commons' financial privilege which date back to the 1670s. These were invoked to prevent peers having a second go, after ambitious MPs predictably jumped to the government whip and overturned the lords. But the deeper reason the government feels it can press on regardless is that the polls suggest that public opinion is on its side.

There is a stark contrast here with the NHS, where the upper house's rewriting of deeply unpopular government plans has a way to go. It seems it's not enough for campaigners to win over unelected peers – they must also find a way to get their argument across to the country.